The present invention concerns a holding arrangement for a device directed at a linearly adjustable roll, for surface treatment of the roll cylinder, with the roll mounted on each end in a machine frame through a bearing housing each. A cylinder/piston unit is provided for each bearing housing for shifting of the roll, and the roll is removable from the machine frame together with the bearing housings.
The starting point of this invention should be seen in the actuating device for actuation of a roll according to the West German patent disclosure 36 10 107 (See U.S. Pat. No. 4,796,452). There, the ends of the roll are mounted in a bearing housing which with the aid of linear guidance elements can be shifted linearly. This linear displacement takes place parallel to a thrust plane which is defined by the axis of said roll and an opposite roll. This makes it possible to bring the roll in contact with the opposite roll and force it onto it, and it can be retracted again from the opposite roll. For the displacement of the bearing housings there is a single-acting cylinder/piston unit provided whose piston is in contact with the bearing housing, displacing it with the thrust force of the piston. The cylinder/piston unit preferably acts upward from below, i.e., against gravity, and at that, specifically perpendicularly. When the cylinder/piston unit is relieved, i.e. pressureless, the roll with the bearing housing rests on the cylinder/piston unit.
A preferred application for actuating devices of this type are wet presses or intermediate calendars of papermaking machines. Further applications are plastic calendars or rolling mills.
The concept of the device consisting of roll and opposite roll, for treatment of web type material, is so selected that in the case of required roll change the opposite roll is removed first so that thereafter the roll with the bearing housings can simply be lifted out upward. This requires no release of any threaded connection since the roll, in operating condition installed and held in place through the bearing housings in the linear guidance elements, can simply be lifted out of these.
This liftoff of the roll from the linear guidance elements connected with the machine frame becomes problematic in the presence of a doctor blade, a blowing device cooling the roll surface or--quite generally--a device for influencing the surface of the roll cylinder which is in contact with the roll. These devices must follow every linear displacement of the roll in order to be able to serve their purpose, and at that, in any roll position. Also, they are supposed to remain in the machine as the roll is lifted out, as long as they are not being replaced themselves.
Thus, the problem is to functionally so integrate auxiliary devices that are coupled with the roll that they will operationally follow the roll displacement, whereas they remain in the machine when the roll is lifted out. Basically, this problem has already been addressed and solved in one fashion in U.S. Pat. No. 1,818,719. There, the roll is mounted in a pivoting lever which supports a doctor blade. However, since pivoting lever constructions are relatively expensive and, consequently, also require a relatively large amount of space, they are unsuited for systems of the above type because here a compact design is required.
In view of the West German patent disclosure 36 10 107 and the United Kingdom application 2 025 480 A, where the linear guidance elements, viewed in the axial direction of the roll, are provided on both ends of the bearing housings, the idea might now be conceived in view of the solution known from U.S. Pat. No. 1,818,719 to mount the above device for influencing the roll surface on the bearing housings. But this would mean that lifting out the roller together with the bearing housings would first require a disassembly of the said device or removing it together with the roll. At any rate, this concept is associated with relatively laborious and expensive manipulations.
Known from the West German patent disclosure 29 46 311 is a solution where a doctor blade is mounted on a fixed frame. But this solution can be successfully applied only in the case of a relatively short displacement stroke. Furthermore, this design requires arranging the doctor blade sideways beside the roll, which as well is considered to be disadvantageous. The greatest disadvantage of this design is that the doctor blade must have lifted off exactly when the probability that the paper web will unintentionally wrap around the roll ("wrapping the roll") is the greatest, namely in closing or opening the roll gap.
The problem underlying the present invention thus is to provide a holding arrangement of the categorial type which with regard to the functional coordination of the device for influencing the roll surface is adjustable toward the roll, which in setting the roll on the opposite roll need not be lifted off, and which in the overall arrangement can be so integrated that it will remain on the machine frame as the roll is lifted out, and at that, without requiring a space-wasting and expensive motional mimetic.